The gush of toxic wastewater that spilled out from a defunct Colorado gold mine last week and turned the Animas River a bright orange-yellow is now estimated to be at least three times larger than initially reported.
The spill occurred on Friday, when workers from the US Environmental Protection Agency (EPA) accidentally breached a mine wall that held back the wastewater, unleashing the flood of toxic sludge. The mine, called Gold King, is located in San Juan County, near the town of Silverton. While the spill was initially estimated to be one million gallons, the agency revised that on Sunday to three million gallons.
Laced with poisonous minerals like arsenic and lead, the wastewater rushed through Cement Creek and into the Animas River, prompting nearby towns, including Silverton and Durango, to switch off their freshwater intake from the river. The EPA, however, said that there is no immediate concern for humans or wildlife due to the spill.
Environmentalists voiced alarm that the agency allowed such a huge reservoir of toxic wastewater to sit in the decommissioned mine for decades.
Jeanne Bassett, a senior associate with activist group Environment Colorado, told VICE News that the accident underscores the threats presented by abandoned mines to wildlife and water supplies.
"This particular mine was last used 92 years ago," she said. "And if you see the picture of the actual mine, it is not obvious that it would hold thousands of gallons of water…. There is a problem when you have created toxic waste and you are not responsible for cleaning it up."
According to Bassett, there are 22,000 abandoned mines in Colorado alone.
While the yellow sludge made its way downstream, Colorado and New Mexico, as well as the Navajo Nation, declared states of emergency in response to the spill.
Navajo Nation President Russell Begaye said he intended to take legal action against the EPA for triggering the spill.
"The EPA was right in the middle of the disaster and we intend to make sure the Navajo Nation recovers every dollar it spends cleaning up this mess and every dollar it loses as a result of injuries to our precious Navajo natural resources," Begaye said in a statement.
Mark Williams, a professor of geography at the University of Colorado said that wastewater drainage from the mines has been a longstanding issue in the region, especially near a silver mine called American Tunnel. About a decade back, the company owning the mine, Sunnyside Gold Corp, plugged American Tunnel using concrete bulkheads.
However, over the past few years, the groundwater level near the mine started rising, causing the water to back up and drain from nearby mines, including Red and Bonita mine and Gold King, through interconnected groundwater channels. The EPA team was working to contain the seepage between the mines when the accident occurred.
Williams said the Gold King spill was unlike anything he had witnessed.
"The color is so intense and so consistent, and it has moved so far downstream. I have not seen this before," Williams told VICE News. "Whether it will have any health impact on humans, depends on the water quality, and so far I have not seen any good information yet on the water quality."
By Sunday afternoon, the plume of toxic wastewater, distinctly visible due to its spectacular color, had nearly reached Nenahnezad, New Mexico, which is more than one hundred miles from the mine, according to the EPA.
While the EPA has released some data about heavy metals in the water and acidity levels, sufficient analysis has yet to be done, experts said.
Meanwhile, the water near the mine in Cement Creek and the Animas river in Silverton — a small town in southwest Colorado — is clearing, even though the mine is still discharging the sludge at about 550 gallons per minute.
The EPA is now diverting the mine water into a series of settling ponds, where it is being treated before it enters Cement Creek. The treatment appeared to be effective, the EPA said in a statement.
The EPA is working with state and local officials to monitor contamination levels. In the meantime, it is providing drinking water to residents adjacent to the river.
Legal action is a near certainty, said Thaddeaus Lightfoot, an environmental law expert with law firm Dorsey & Whitney.
"The EPA frequently hires emergency contractors to address the release of hazardous substances at mining and other industrial and commercial facilities," Lightfood said. "Where EPA contractors have made such mistakes in the past, courts have held them liable for any additional remediation … despite statutory immunity provisions."
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